Examples with PSODecipher org.openecard.sal.protocol.genericcryptography.apdu.PSODecipher used on opensource projects

Example 1 with PSODecipher

use of org.openecard.sal.protocol.genericcryptography.apdu.PSODecipher in project open-ecard by ecsec.

the class DecipherStep method perform.

@Override
public DecipherResponse perform(Decipher request, Map<String, Object> internalData) {
    DecipherResponse response = WSHelper.makeResponse(DecipherResponse.class, WSHelper.makeResultOK());
    try {
        ConnectionHandleType connectionHandle = SALUtils.getConnectionHandle(request);
        String didName = SALUtils.getDIDName(request);
        byte[] applicationID = connectionHandle.getCardApplication();
        CardStateEntry cardStateEntry = SALUtils.getCardStateEntry(internalData, connectionHandle);
        Assert.securityConditionDID(cardStateEntry, applicationID, didName, CryptographicServiceActionName.DECIPHER);
        DIDStructureType didStructure = SALUtils.getDIDStructure(request, didName, cardStateEntry, connectionHandle);
        CryptoMarkerType cryptoMarker = new CryptoMarkerType(didStructure.getDIDMarker());
        byte[] keyReference = cryptoMarker.getCryptoKeyInfo().getKeyRef().getKeyRef();
        byte[] algorithmIdentifier = cryptoMarker.getAlgorithmInfo().getCardAlgRef();
        byte[] slotHandle = connectionHandle.getSlotHandle();
        // See eGK specification, part 1, version 2.2.0, section 15.9.6.
        if (didStructure.getDIDScope().equals(DIDScopeType.LOCAL)) {
            keyReference[0] = (byte) (0x80 | keyReference[0]);
        }
        TLV tagKeyReference = new TLV();
        tagKeyReference.setTagNumWithClass(0x84);
        tagKeyReference.setValue(keyReference);
        TLV tagAlgorithmIdentifier = new TLV();
        tagAlgorithmIdentifier.setTagNumWithClass(0x80);
        tagAlgorithmIdentifier.setValue(algorithmIdentifier);
        byte[] mseData = ByteUtils.concatenate(tagKeyReference.toBER(), tagAlgorithmIdentifier.toBER());
        CardCommandAPDU apdu = new ManageSecurityEnvironment((byte) 0x41, ManageSecurityEnvironment.CT, mseData);
        apdu.transmit(dispatcher, slotHandle);
        byte[] ciphertext = request.getCipherText();
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        BigInteger bitKeySize = cryptoMarker.getCryptoKeyInfo().getKeySize();
        int blocksize = bitKeySize.divide(new BigInteger("8")).intValue();
        // check if the ciphertext length is divisible by the blocksize without rest
        if ((ciphertext.length % blocksize) != 0) {
            return WSHelper.makeResponse(DecipherResponse.class, WSHelper.makeResultError(ECardConstants.Minor.App.INCORRECT_PARM, "The length of the ciphertext should be a multiple of the blocksize."));
        }
        // decrypt the ciphertext block for block
        for (int offset = 0; offset < ciphertext.length; offset += blocksize) {
            byte[] ciphertextblock = ByteUtils.copy(ciphertext, offset, blocksize);
            apdu = new PSODecipher(ByteUtils.concatenate(PADDING_INDICATOR_BYTE, ciphertextblock), (byte) blocksize);
            CardResponseAPDU responseAPDU = apdu.transmit(dispatcher, slotHandle);
            baos.write(responseAPDU.getData());
        }
        response.setPlainText(baos.toByteArray());
    } catch (ECardException e) {
        response.setResult(e.getResult());
    } catch (Exception e) {
        logger.error(e.getMessage(), e);
        response.setResult(WSHelper.makeResult(e));
    }
    return response;
}